Elevator control system



May 23, 1933.

MAIN MOTOR BRAKE 22 G. N. CRABBE ELEVATOR CONTROL SYSTEM BRAKE REZLIEASE MOTOR 30 3 Sheets-Sheet 1 HEAVE 45 CONTROL 000R o zmmm; 000R opcnmuc P'IOTOR56 omma PANEL l 1 I I Q a AUXILIARY 66 MOTOR BRAKE 53 AUXILIARY Mom? 452 1% 26 IN use LIGHT 31 m uss LIGHT Z57 COUNTERWEIGHT Z34 W155 234 \O LUIMQ LUl53-u, 263

7 2m CALL BUTTON I14 :70 CALL Burrow H4 noon CLOSING BUTTON us uooflcmsmcsu'rrouus SEND BUTTON n 260 SENDBUTTON H3 LANDING PLATFORM a .1264 LANDING PLATFORM 46 r a s Q L LDBI IN use UGHT m use LIGHT I ELEVATOR CAR fggg 465 0005255 25o ogggs 25 Q 261 m sewn BUTTON SEND au'r'ron n2 CALL BUTTON 5 Ewes: nu-r-ron n5 DOOR CLOSINGBUTTON n1 11 4 cmsmsauflowlfl 68 Z LA D P [:0 r1 RPLATFORMS LANDING PLATFORM N 'AA R 264' 57 5 2 45 gg m PL L =1- 21! u m 272 INVENTORS ATTORNEY May 23, 1 e. N. CRABBE El AL ELEVATOR CONTROL SYSTEM Filed Jan. 16, 1930 3 Sheets-Sheet 2 (CTR FIG. 2

Y E N m H A May 23, 1933- G. N. CRABBE El AL 15 ELEVATOR CONTROL SYSTEM Filed Jan. 16, 1950 3 Sheets-Sheet 3 INVENTORS ATTORNEY Patented May 23, 1933 UNITED STATES PATENT OFFICE GEORGE NORM CRABBE, OE CBESSKILL, NEW JERSEY, AND SAMUEL GUSTAVE MARGLES, OF BROOKLYN, NEW YORK, ASSIGNORS TO OTIS ELEVATOR COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY ELEVATOR CONTROL SYSTEM Application filed January 16, 1930. Serial No. 421,216.

The invention relates to elevator control systems and particularly to systems for controllin both the operation of the elevator car and the operation of closure means which control access to the elevation car.

In the early development of the elevator art, it was recognized that there were certain advantages in arranging the elevator system so as to be under the control of an operator in the elevator car for certain types of installations and it was also recognized that there were certain advantages in arranging the elevator system so that the operation of the car could be controlled by the passengers and intendin passengers themselves for other types 0 installations. In those systems in which the passengers and intending passengers themselves have control of the car, push buttons are usually provided for effecting the various control operations. It was also found desirable in the push button types of systems to provide power mechanism for operating the hatchway doors and car gate. In some instances, the systems are arranged so that the mechanism for operating the doors and gates is subjected to the control of the push buttons themselves or to other control switches specifically-provided for that purpose. Among the various types of push button control systems in which it has been found desirable to effect automatic operation of the doors and gates are those particularly adapted for the handling of freight or similar systems, usually referred to as push button control freightelevators. The invention is particularly adapted to elevator installations of the push button control freight type, although certain features of control to which the invention is directed are applicable to various types of elevator installations, including passenger elevator systems.

The invention will be described as applied to a freight elevator installation in which the elevator car .is employed to carry baggage or other article carrying trucks, particularly automotive trucks operated by an attendant, from one level to another, as for example in railway terminals. It is desirable in such installations that the hatchway doors at various landings be automatically operated, because their manual operation would quite frequently be inconvenient. It is also desirable that both the opening and closing of the hatchwa doors and the calling of the car to a lan ing, be effected automatically by the truck itself, thereby relieving the truck attendant of the necessity of leaving the truck to effect such operation through manual controls. It is further desirable that push buttons or other manual controls be provided to control both the hoisting mechanism for the elevator car and the operating mechanism for the hatchway doors so that the manual control of the elevator car and hatchway doors may be effected when desired. In this connection it is of advantage that the car may be caused to remain at any landing by operating a manual control thereat so that the use of the elevator car thereat at certain times, as for example at the times when trains are due to arrive in railway terminals, may be assured.

One feature resides in causing the car to be brought from any landing to another landing automatically when a load for the car, such as a truck or a person, comes up to the hatchway door at that other landing.

Another feature of the invention is to cause the opening of the hatchway door at a landing to be effected automatically by a load for the car at that landing upon the arrival of the elevator car at the landing, in the event that the car has been brought to the landing by said load for the car.

Still another feature is to cause the hatchway door at a landing at which the car is positioned to open automatically when a load for the car comes up to the door.

A fourth feature of the invention resides in rendering manual controls effective to close the hatchway door at a landing at which the car is positioned and to dispatch the car to another landing when the elevator car is occupied.

A fifth feature is to cause the hatchway door at a landing to open automatically upon the arrival of the car thereat when the car is occupied.

A sixth feature resides in causing the hatchway door at the landing at which the car is positioned to be closed automatically when a load for or from the car moves away from the hatchway door, rovided there is no other load remaining ad]acent the door or in the car.

A seventh feature resides in rendering loads for the car and manual controls at landings other than that at which the car is positioned ineffective to control the operation of the elevator car when the elevator car is occupied.

An eighth feature is the provision of a manually operable control at one or more landings operable to call the car to the landing at which the control is located and to render loads for the car and manual controls at other landings ineifective to control the operation of the elevator car.

A ninth feature resides in causing the hatchway door at a landing to be opened and maintained open by the manually operable call control at that landing when the car is at the landing.

A tenth feature is to provide an elevator car arranged to permit access thereto at a plurality of sides thereof in conjunction with a movable approach located before the hatchway doors at such sides at each landing for controlling the operation of the hatchway doors and also the operation of the elevator car.

Other features and advantages will be apparent from the following description and appended claims.

In carrying out the invention, according to the embodiment illustrated, the elevator car is arranged for entrance and exit at opposite sides thereof and corresponding entrances and exits are provided at each landing. A hatchway door is provided for each entrance and exit opening at the landings and suitable mechanism is provided for opening and closing these doors. A movable platform is arranged at each landing in the floor in front of each hatchway door, these platforms being located so as to be depressed by a truck approaching or leaving the elevator at either side of the hatchway. These platforms, upon depression, are arranged to' control the operating mechanism for the hatchway doors and the hoisting mechanism for the elevator car. When a platform is depressed at a landing at which the car is positioned, this causes the opening of the hatchway doors at that landing. In the event that the car is at some other landing, this causes the car to be brought to the landing at which the platform is depressed and the doors to open upon the arrival of the car at that landing.

One or more sets of push buttons are provided in the car, each set having one button for each landing, and one or more sets of push buttons are provided at each landing,

each set having one button for each of the other landings. These buttons are for disatching the car to the landings corresponding to the buttons pushed. A movable platform is also provided in the elevator car. Vhen this car platform is depressed, the send buttons at the landings at which the car is positioned and the car buttons are rendered effective to cause the hatchway doors at the landing to close and to cause the car to be dispatched to another landing. Upon the arrival of the car at such other lanrline the hatehway doors at that landing automatically open. When the truck is removed from the car, it causes the platform at that landing to be depressed, maintaining the doors in open position and, upon restoration of the landing platform to raised position, the hatchway doors automatically close.

One or more call buttons are provided at each of the landings or at only certain of the landings and are operable to cause the hoisting mechanism to bring the car to the landing at which the call button is operated and to cause the door operating mechanism to open the hatchway door at that landing upon the arrival of the car thereat, in the event the car is positioned at another landing at the time the call button is operated, and to cause the door operating mechanism to open the hatchway doors at the landing at which the call button is operated, in the event the car is ositioned at that landing at the time the cal button is operated. \Vhen the doors are open in response to the operation of a call button they are caused to remain open, even though no load is on the car platform or the landing platforms at that landing. One or more door closing buttons are provided at each landing at which a. call button is located. In the event that the hatchway doors at any landing have been opened as a result of the operation of a call button at that landing, the closing of these doors may be effected by operating a door closing button at that landing. The doors may also be reclosed after a load is placed in the car by operating the car button or a send button at that floor to dispatch the car to another floor. Lamps are provided at certain or all of the floors and are lighted, when the car is under the control of a call button, to indicate that the car is in use. When a landing platform or the car platform is depressed, the landing platforms and call buttons at other floors are ineffective to control the operation of the car or the operation of the hatchway doors. Similarly, when a call button has been operated and maintains control of the car, the landing platforms and call buttons at other floors are ineffective to control the operation of the car and the operation of the hatchway doors.

In the drawings:

Figure 1 is a view of an elevator installation illustratingschematically apparatus suitable for carrying out the present invention.

Figure 2 is a schematic representation of the hatchway doors and operating mechanism therefor, according to Figure 1, for one side of the hatchway, the doors being viewed from the interior of the hatchway; and.

Figure 3 is a simplified wiring diagram of the power and'control circuits.

For a general understanding of the invention, reference may be had to Figure 1 wherein various parts of the system are indicated by legend. The system will be described for a two floor installation. It is to be understood however, that the s stem may be arranged for any number 0 floors, t wo be1ng chosen merely for purposes of description.

The numeral 250 designates an elevator car which is raised and lowered in the elevator hatchway by means of a hoisting motor 11. This motor drives the hoisting sheave 251 over which pass the hoisting ropes 252 connected at their ends to the elevator car and counterweight 253. The elevator motor is controlled by various electromagnetic switches mounted on a control panel 254. The brake for the elevator motor is designated by the numeral 22. The shoes of thls brake are arranged to be released by a motor designated 21.

Levelling mechanism, designated as a whole by numeral 255, is provided for bringing the car to an exact landing level in stopping. This mechanism is carried by the car and is arranged to be actuated by levelling cams 256 and 257, provided in the hatchway for each landing and positioned to cooperate with the operating rollers of the levelling mechanism to effect the levelling operation. The levelling mechanism acts through electromagnetic switches mounted on control panel 254 to control the hoisting mechanism to effect the levelling operation, as for example by controlling an auxiliary motor 26 arranged for connection to the hoisting sheave 251. This connection may be effected by arranging the brake 22 to act, when applied, as a clutch for connecting the auxiliary motor to the motor 11, as is known in the art. A brake 33 is provided for the auxiliary motor for bringing the elevator car to a stop when the exact landing level is reached. The release coil for brake 33 is designated 32. M0- tor 11 will hereinafter be referred to as the main motor to distinguish it from the auxiliarv motor 26.

Hatchway doors 258 are provided at opposite sides of the hatchway at each landing for affording access to and exit from the elevator car. All the hatchway doors on one side of the hatchway are to be operated by a motor 36. Similarly, all the hatchway doors on the other side of the hatchway are operated' by a motor 39. Door locking mechanism designated as a whole by 260 is provided for each door. These door locking mechanisms are operated by cams 261 carried by the elevator car to effect the unlocking of the doors. A movable platform is located before each hatchway door at each landing and is arranged to operate switches for controlling the operation of the elevator car and the operation of the hatchway doors. A movable platform is also provided in the elevator car and is arranged tooperate switches for controlling the operation of the elevator car and the operation of the hatchway doors. The car platform may be in sections as shown in Figure 1, particularly in case of large cars arranged to accommodate several baggage trucks. When the platform is divided into sections, the sections are arranged so that when a load is placed in the car it will depress at least one of the sections. Springs are illustrated in connection with the movable landing platforms and the movable car platforms to indicate that each of these platforms is biased to its raised position.

Two sets of push buttons are provided in the elevator car for controlling the. operation of the car. The push buttons 110 and 111 of each set, which will hereinafter be referred to as car buttons, control the dispatching of the cars to the landings while the push buttons 118 of each set are stop buttons provided to enable the car. to be stopped, as in an emergency. The two sets of push buttons are arranged at opposite sides of the car for the convenience of its occupants.

A set of push buttons is provided at each side of the hatchway at each landing. The push buttons 112 of each. set at the lower landing and the push buttons 113 of each set at the upper landing are adapted to control the operation of the car to send the car from the lower landing to the upper landing and to send the car from the upper landing to the lower landing respectively. The push buttons 114 of each set at the upper landing and the push buttons 115 of each set at the lower landing serve as call buttons, and also serve to control the opening of the hatchway doors at their respective landings. The push buttons 11? of each set at the lower landing and the push buttons 116 .of each set at the upper landing serve to control the closing of the hatchway doors when the car is positioned at the landing at which these push buttons are located.

Lanterns 224, provided at each side of the hatchway at the lower landing, and lanterns 234, provided at each side of the hatchway at the upper landing, serve as signals to indicate that the car is in use.

A group of control switches, designated generally as LU and LD are provided on the hatchway wall at each landing and are adapted to be operated by a cam 262 carried by the car to control-the operation of the elevator car and also of the hatchway door operating ll. sections in opening and closing move simultaneously in opposite directions in the same vertical plane. Each of the doors comprises an upper section 263 and a lower section 264 connected as by cables 265 passing over pulleys 266. The sections and 264 are movable in guides (not shown).

Each section is provided with a hanger bar 267, projecting beyond each side thereof, to which one end of cable 265 is connected while the other end of the cable is connected to the corresponding section 263. Each lower section 264 overbalances the corresponding upper section 263 so that a lower section, when released, descends to open position by gravity and through cable 265 causes the upper section to move upwardly. \Vhen a lowor section 264 descends and is fully open, its top edge is substantially flush with the landing platforms and the car platforms, thus obviating any appreciable gap therebetween.

The doors are locked in closed position by their locking mechanisms 260. Each of these locking mechanisms comprises two latching devices arranged on each side of the door. As these latching devices are of the same construction, only one of them will be described. It comprises a lever 268 pivoted on the hatchwav wall at the side of the door. The end 276 of the lever 268 normally rests beneath the hanger bar 267 to prevent the descent of the section 264. The lever 268 is connected to a lever 271, pivoted to the hatchway wall. Lever 271 has an impact member 272 normally positioned by spring 273 to be engaged by one of the cams 261 carried by the elevator car 250.

Two operating cables 274 are provided for the hatchway doors on each side of the hatchway. These cables extend throughout the height of the hatchway and have connection with the doors through blocks 275, arranged beneath the hanger bars. The cables 27 4 for the doors on one side of the hatchway pass over sheaves 276 at their upper ends and are joined to a connector 277 secured to acable 278. The free ends of the cables 274 have weights 280 attached thereto to maintain them taut. The cable 278 is passed around the drum 281 of a winch 282 which is operable in either direction by the motor 36. From the winch drum the cable 278 passes over sheaves 283 and is connected to a weight 284 slidable in guides 285. The cable connector 277 has a projection 286 which, when the doors are closed, bears against an arm of a spring closed door limit switch, diagrammatically shown at 167, to keep the bridge for the switch contacts disengaged therefrom. Projection 286 is also adapted to bear against an arm of a normally spring closed door limit switch 160, to keep the bridge for the switch contacts separated therefrom when the doors are open. The door limit switches 160 and 167 are arranged in circuits for controlling the operation of the door operating motor 36 in a manner which will be hereinafter described. The weight 284 in addition to taking up slack in the cable 278 resulting from operation of the winch drum 281 by motor 36 serves to operate a switch 92. When the doors 258 are fully closed, the weight 284 is in its lowermost position and causes the contacts of switch 92 to be bridged. This switch is arranged in a circuit for controlling the operation of the elevator car so as to prevent the operation of the car when the contacts of the switch are not bridged. The motor 36 is arranged to drive the drum 281 through suitable gearing and an electromagnetic brake 43 is provided for bringing the motor to a stop upon deenergization thereof.

The arrangement of the operating mechanism and associated parts for the doors on the other side of the hatchway is the same and will not be described.

The hatchway doors are opened and closed as follows :VVhen the elevator car arrives within the door operating zone ata landing the cams 261 engage the impact members 272 associated with the doors at that landing and rock levers 271 to effect the removal of the ends 270 of levers 268 from contact with the underside of hanger bars 267. The sections 264 of the doors are then held in closed osition only by the blocks 275 in contact wit the underside of hanger bars 267.

The circuits for the motors 36 and 39 are completed, in a manner to be described, causing the motors to rotate the winch drums in a direction to pay out the ends of cables 278 attached to connectors 277. This results in the paying out of cables 274. As cables 274 are paid out, the weights 280 act to prevent any slack developing in these cables, and also in cables 278 between connectors 277 and winch drum 281 as the winches move the weights 284 upwardly in guides 285. Upward movement of weights 284 causes the disengagement of the bridges from the contacts of switches 92 to open the control circuits for the elevator car. When the winches start to pay out cables 278, the projections 286 move away from the arms of door limit switches 167, causing the contacts of these switches to be bridged.

As the cables 274 move downwardly, blocks 275 for all the doors move therewith. The hanger bars 267 and the sections 264 of the unlocked doors follow the blocks 275. Sections 264 in moving downwardly act through the cables 265 to move the corresponding sections 263 upwardly. As the latch levers 268 are released only at the floor at which the elevator car 250 is located the sections 263 and 264 of the doors at other landings are kept latched together and the blocks 275 on cables 274 which abut the hanger bars 267 of these doors merely move away from the hanger bars. The cables 274 are paid out until the projections 286 strike the arms of switches 160 causing the circuits of the motors 36 and 39 to be interrupted whereupon the motors stop as brakes 43 are applied. The doors at the landing at which the elevator car is located are in open position at this time.

When the circuits for motors 36 and 39 are completed for reverse operation, as will be later described, the winches are rotated in a direction to haul in cables 274. The weights 284 descend in guides 285 to take up the slack in cables 278 and rojections 286 move away from the arms 0 door limit switches 160 whose contacts are bridged. Cables 278 act through connectors 277 to pull cables 274 upwardly, the blocks 275 thereon causing hanger bars 267 and sections 264 of the open doors to be lifted. Sections 263 of the open doors descend of their own weight taking up the slack in cables 265. The sections 263 and 264 of the open doors are thus moved towards each other to closed position. When projections 286 abut the arms of the door limit switches 167, the bridges for the contacts of switches 167 are removed disabling the circuit of motors 36 and 39, whereupon the brakes 43 are applied and the motors stopped. The doors at this time are in closed position. The weights 284 having descended are now in their lowermost positions wherein the contacts of switches 92 are bridged.

When the'elevator car moves away from the floor the latching mechanism locks the hatchway doors in closed position.

The arrangement of the doors, the operaating mechanism therefor, and associated parts, as above described, have been chosen merely for convenience of description, and it is to be understood that other arrangements of doors, door operating mechanism, anddassociated parts may be employed if desire Reference may now be had to Figure 3 which illustrates diagrammatically the various control and power circuits. A three phase alternating current power supply is illustrated but it is to be understood that the principles of the invention are equally applicable to direct current systems. The supply mains are indicated by the numerals 5, 6 and 7. A service switch 8 is provided for connecting the power circuits and the primary winding of a transformer 10 to the supply mains.

The main motor 11 is illustrated as of the polyphase induction type provided with resistances for controlling the voltages applied to its stator windings. The rotor of the main motor is designated 12 and its stator windings are designated 13, 14 and 15. The resistances for controlling the voltages applied to the stator windings are designated 16, 17 and 18. 20 is the rotor of the motor 21 for releasing the brake 22 for main motor 11, and 23, 24 and 25 are the stator windings of the brake release motor. The rotor of auxiliary motor 26 is designated 27, its stator windings 28, 30 and 31, and 32 is the release coil of the brake 33 for the auxiliary motor. The levelling switches, operated by the levelling mechanism hereinbefore referred to, are designated 34 and 35.

For purposes of simplification of the wiring diagram only one of the door operating motors is illustrated, namely motor 36, the control for door operating motor 39 being effected in the same manner as for motor 36.

The numeral 37 designates the rotor of motor 36, while numerals 38, 40 and 41 designate its stator windings. The release coil of the brake 43 for motor 36 is designated by the numeral 42.

The movable landing platforms at the lower landing are designated 44 and 45 and the landing platforms at the upper landing are designated 46 and 47. The numeral 48 designates a switch, the contacts of which are adapted to be bridged when the platform 44 is depressed, and the numeral 50 designates a switch having contacts adapted to be bridged when the platform 44 is in raised position. Similar switches 51 and 52, 53 and 54, 55 and 56,-are provided for the platforms 45, 46 and 47 respectively. The movable car platforms are designated 57 and 58. The car platform 57 on depression is adapted to cause.

the bridging of the contacts of a switch 60. The contacts of a switch 61 are adapted to be bridged when car platform 57 is in raised position. Similar switches 62 and 63 are provided for the car platform 58.

The various safety devices, such as final limit switches, the switch operated by the car safety brake, the governor operated switch, reverse phase and overload relays have been omitted. Certain of these switches have been indicated generally at 64 to indicate their positions in the control circuits.

The various electromagnetic switches and relays employed are mounted on the control panel 254 and are designated as follows A-Main motor up direction switch,

BMain m'otor down direction switch,

CFirst accelerating switch,

KSecond accelerating switch,

P-Main motor potential switch,

MA-Auxiliary motor up direction switch,

MB-Auxiliary motor, down direction switch,

RAuxiliary motor retarding switch.

AA-Main motor up auxiliary direction switch,

BB-Main motor down auxiliary direction switch,

U-Main motor up direction relay,

D-Main motor down direction relay,

TNon-interference switch,

X-Door opening switch,

Y-Door closing switch,

Z-Auxiliary door control switch,

F-Upper landing door holding switch,

G-Lower landing door holding switch,

E-Door releasing relay.

Throughout the following descri tion these letters, in addition to various re erence numerals, will be applied to the parts of the above enumerated switches and relays. For example, A93 designates contacts of the main motor up direction switch A while P103 designates the actuating coil of the potential switch.

Assume that the elevator car is not loaded and is at rest at the lower landing and that all the hatchway doors 258 are in closed position. Assume also that there is no load on any of the movable landing platforms. When the service switch 8 is closed current is supplied to the primary winding of the transformer 10. Current is induced in the secondary winding of transformer 10 resulting in energization of the actuating coil Z of the auxiliary door control switch. The circuit for coil Z65 may be traced from the left-hand end of the transformer secondary winding through stop buttons 118, wire 66, wire 67. coil Z65, wire 68, limit switch LD70, closed as the car is at the lower landing, landing platform switch 50, landing platform switch 52, contacts G71 of lower landing door holding switch, car platform switches 61 and 63. and wire 72, to the other end of the transformer secondary winding. Energization of coil Z65 effects the separation of contacts Z73 and the engagement of contacts Z74. The engagement of contacts Z74 prepares the circuit for actuating coil Y75 of the door closing switch Y. The separation of contacts Z73 opens the circuit for actuating coil X76 of the door opening switch.

Assume now that a load, such as a baggage handling truck, is moved onto platform 46 at the upper landing. The weight of the truck causes the landing platform 46 to be depressed, efi'ecting the opening of switch 54 and the closing of switch 53. The purpose of switch 54 will appear as the description proceeds. The closing of switch 53 completes a circuit from wire 66, through contacts T77 of the non-interference switch, wire 78, wire 79, coil AA80 of the main motor up auxiliary direction switch, landing platform switch 53, limit switch LD81 which is closed since the elevator car is at the lower landing, and contacts G82, to wire 72. The energization of coil AA80 results in the engagement of contacts AA83 and consequent energization of actuating coil A84 of the main motor up direction switch. The circuit for coil A84 may be traced from the left-handside of the transformer secondary winding, through stop buttons 118, contacts MA85 of the auxiliary motor up direction switch, contacts M1386 of the auxiliary motor down direction switch, wire 87, contacts B88 of the main motor down direction switch, limit switch contacts LU90 for the upper landing, which are engaged since the car is at the lower landing, contacts AA83, coil A84, wire 91, door switches 92 and safety devices 64 to wire 72. The energization of coil A84 results in the separation of contacts A93 and A94 and the engagement of contacts A95, A96, A97, A98 and A99.

The separation of contacts A93 further opens the circuit for actuating coil B100 of the main motor down direction switch. The separation of contacts A94 opens the circuit for the actuating coils of the auxiliary motor direction switches and also the circuit for the actuating coils of the switches X and Y for the door operating motor 36, thus preventing energization of auxiliary motor 26 and door motor 36. Contacts A95, on engagement, establish a holding circuit through wire 101 for coil A84. Contacts A97, on engagement, prepare the circuit for brake releasing motor 21. Contacts A98, on engagement, prepare a circuit for actuating coil R108 of the retarding switch for auxiliary motor 26. Contacts A98 and A99, on engagement, prepare the circuits for main motor 11 for an operation to move the car in the up direction. Contacts A96, on engagement, effect the energization of actuating coil T102 of the non-interference switch and actuating coil P103 of the main motor potential switch. The circuits for coils T102 and P103 mav be traced from the secondary of transformer 10 through the contacts of stop buttons 118, contacts MA85, contacts M1386, wire 104, wire 105, contacts A96, wire 106, through coil P103 and coil T102 in parallel, wire 91, the contacts of door switches 92, and safety devices 64, to wire 72.

The energization of coil T102 results in the engagement of contacts T107 and the separation of contacts T77. The engagement of contacts T107 establishes a holding circuit for coil T102 and P103. The separation of contacts T77 opens the circuits for the main motor up and down auxiliary direction switch coils AA80 and B13156 to prevent interference with the trip of the car to the upper floor. Upon the deenergization of coil AA80 contacts AA83 separate. Contacts A95 of the main motor up direction switch maintain coil A84 energized to prevent the opening of the up direction switch.

The energization of coil P103 results in the engagement of contacts P122 and P123. The engagement of contacts P123 together with the engagement of contacts A98 completes the circuit for actuating coil R108 of the auxiliary motor retarding switch. This circuit may be traced from supply main 5, through the left-hand blade of service switch 8, wire 124, contacts P123, wire 125,wire 126, contacts A98, wire 127, coil R108 and wire 128, the middle blade of switch 8 to supply main 6. Energization of coil R108 effects the separation of contacts R130 to further open the circuits for the actuating coils of the direction switches for auxiliary motor 26 to prevent its operation while the main motor 11 is in operation. The engagement of contacts P123 together with the engagement of contacts A98 also connects stator winding 13 of main motor 11 to wire 124 of the power circuits. The circuit for winding 13 is from the wire 124, through contacts P123, wire 125, wire 126, contacts A98, starting resistance 16, stator winding 13, to the star point. The engagement of contacts P122 connects stator winding 14 of motor 11 to wire 128 of the power circuits. This circuit is from wire 128, through contacts P122, wire 132, wire 131, resistance 17, winding 14, to the star point. The circuit for winding 15 may be traced from supply main 7, through the right-hand blade of service switch 8, wire 133, contacts A99, starting resistance 18, stator winding 15, to the star point. The engagement of contacts P123 connects stator winding 23 of brake release motor 21 to wire 124 of the power circuit. The circuit for winding 23 may be traced from wire 124, through contacts P123, wire 125, stator winding 23 to the star point. The engagement of contacts P122 connects stator winding 24 to wire 128 of the power source. The circuit for winding 24 may be traced from wire 128, through contacts P122, wire "132, and stator winding 24 to the star point. Stator winding 25 of brake motor 21 is connected'to wire 133 of the power mains by contacts A97 and A99. The circuit for winding 25 may be traced from wire 133, through contacts A99, wire 134, contacts A97, stator winding 25, to the star point.

The energizatfon of the stator windings 23, 24 and 25 results in the operation of brake motor 21 to release the brake 22 and interrupt the mechanical connection of auxiliary motor 26 to the hoisting sheave 251. The energization of the stator windings 13, 14 and 15 results in starting main motor 11 to move the elevator car in the up direct on. The actuating coil C135 of the first accelerating switch is connected for energization across the power wires 124 and 133. The operation of this switch is delayed, as by a dashpot (not shown). Upon operation, switch C causes the engagement of contacts C141 C142, C143 and C144. The engagement of contacts C141, C142, and C143 results in shortcircuiting part of the starting resistances 16, 17 and 18 respectively. The engagement of contacts C144 connects the actuating coil K145 of the second accelerating switch across the power wires 124 and 133. The energization of coil K145 causes engagement of contacts K146, K147 and K148, short-circuiting the remaining portion of starting resistances 16, 17 and 18 to connect the stator of motor 11 directly to the power circuit, thus causing full voltage to be applied to the stator windings, the operation of switch K also being delayed, as by a dash-pot (not shown).

When the elevator car moves away from the floor the latching mechanism locks th hatchway doors in closed position. 1

As the elevator car leaves the lower land mg the cam 262 carried by the car moves out of engagement with the operating arms of the limit switches LD150, LD151, LD and LD81 at the lower landing in succession. The limit switches LD'81, LD70, and LD151 are opened and limit switch LD150 is closed. The closing of limit switch LD150 prepares the circuit for actuating coil B100 of the main motor down direction switch. However, coil B100 is not energized as contacts A93 opened this circuit on operation of the up direction swltch. The limit switches LD70 and LD151 are operated simultaneously. On opening ofu I I o pares the circuit for actuating coil X76 of the door opening switch. The separation of contacts Z74 opens the circuit for actuating coil Y75 of the door closing switch. The separa-. tion of contacts LD151 further opens the circuit of coil Y7 5 and also opens the circuit of door opening switch actuating coil X76. The circuit for the door opening coil X76 and door closing coil Y7 5 is also open in wire 152, because of the separation of contacts A94 of the up direction switch. The contacts LD81 on separation maintain the circuit for coil AA of the up auxiliary direction switch interrupted.

Upon approaching the upper landing the cam 262 carried by the car effects the closing of switches LU153, LU154, LU155 and the opening of switch LU9O in succession. The closing of switch LU153 prepares the circuit for actuating coil B13156 of the down auxiliary direction switch. The closing of switch LU154 prepares the circuit through wire 69 for coil Z65. However, this circuit is maintained open by the platform switch 54, which is open. The closing of switch LU155 prepares the circuit of actuating coil X76 of the door opening switch. This circuit remains uncompleted as contacts A94 of the up direction switch are separated. The opening of switch LU-results in the deenergization of actuating coil A84 of the up direction switch.

Upon deenergization of coil A84, contacts A93 and A94 engage and contacts A95, A96,

,. switch,

The separation of contacts A98 and A99 interrupts the circuits for the stator windings of main motor 11 and for accelerating switch coils C135 and K145. The separation of contacts A97 and A98 opens the circuits for the stator windings of brake release motor 21 and results in the application of brake 22 to stop the main motor and bring the car to rest at the upper landing. When brake 22 is applied auxiliary motor 26 ismechanically connected through main motor 11 for driving hoisting sheave 251, as is known in the art.

Although contacts A96 separate when coil A84 is deenergized coils T102 and P103 remain energized as contacts T107 maintain a holding circuit for these coils.

Upon reaching the door operating zone at the upper landing, the cams 261 carried by the car engage the impact members 272 of latch levers 271 to unlock the hatchway doors at the upper landing. The doors however are held in closed position by the blocks 275 abutting the hanger bars 267. The engagement of contacts A94 results in the preparation of the circuits for the actuating coils of the direction switches of auxiliary motor 26 and the completion of the circuit for the actuating coil X76 of the door opening switch. The circuit for coil X7 6 may be traced from wire 66. through wire 158, coil X76, contacts Z73, engagedsince coil Z65 is deenergized, contacts 160, engaged since the. hatchway doors are in closed position, contacts LU155 engaged as the elevator car approached the upper landing. wire 161, wire 152, contacts A94, contacts B162, to wire 72. Coil X76 on energization effects the engagement of contacts X163 and X164 to connect the stator windings of door operating motor 36 to the power circuit. The circuit for stator winding 38 is from wire 124, through wire 165, contacts X163, winding 38, to the star point. The circuit for stator winding 40 is from wire 133, through wire 166, contacts X164, stator winding 40, to the star point. The stator winding 41 is connected directly to wire 128. Brake release coil 42 is connected across stator windings 38 and 40. Upon the release of brake 43 and energization of the stator windings of door operating motor 36, the motor operates to permit hatchway door 258 to move to open position as previously described. As the doors move from closed position door switch 92' opens and door switch 167 closes.

The opening of door along with the opening of door switch 92 for the hatchway door at the opposite side of the hatchway. results in the deenergization of coils T102 and P103. Upon deenergization of coil T102, contacts T107 separate and contacts T77 engage. The separation of contacts T107 is in preparation for a subsequent operation. The engagement of contacts T77 prepares the circuits for the actuating coils AA80 and B13156 of the auxiliary direction switches for the main motor. The deenergization of coil P103 results in the separation of contacts P122 and P123, these contacts con trolling the circuits for main motor 11 and brake release motor 21, already open as a result of the separation of contacts A97, A98 and A99. The opening of switches 92 also opens the control circuits to prevent energization of the actuating coils A84 and B100 of the direction switches of the main motor 11. Thus when the hatchway doors are not in closed position the main motor 11 cannot be employed to operate the elevator car.

The closing of door switch 167 prepares the circuit for actuating coil Y of the door closing switch. When the hatchway door sections reach open position switch 160 is opened as previously described and results in deenergization of coil X76. On deenergization of coil X76, contacts X1633 and 164 separate to deenergize brake release coil 42 and door operating motor 36, and the motor stops as the brake 43 is a plied.

If, as the circuits 0 main motor 11 are interrupted and brake 22 is applied, the elevator car platform is below the upper landing, the levelling mechanism 255 on the car is operated by levelling cam 257 in the hatchway to effect the closing of levelling switch 34. The closing of switches 34 together with the engagement of contacts A94 prepares the circuit for actuating coil MA170 of the up direction switch for auxiliary motor 26.

Upon the deenergization of actuating coil A84 of the up direction switch for main motor 11 the separation of contacts A98 results in deenergization of actuating coil R108 of the retarding switch for auxiliary motor 26. On deenergization of coil R108, contacts R130 start to engage. The engagement of contacts R130 is delayed for an interval by a dash-pot 157 associated with the retarding switch to prevent completion of the circuits for auxiliary motor 26 until a predetermined time after the circuits for main motor 11 are interrupted. On engagement of contacts R130 at the end of the interval provided by dash-pot 157 the circuit for the actuating coil of one of the direction switches of auxiliary motor 26 is completed. As the closing of levelling switch 34 and the engagement of contacts A94 have prepared the c rcuit for coil MA170, the engagement of contacts R130 results in energization of coil MA170. The circuit for coil MA170 may be traced from wire 66, through wire 171. contacts R130, coil MA170, contacts M13172, levelling switch 34. wire 152, contacts A94, contacts B162. to wire 72. Energization of coil MA170 effects the en agement of contacts MA173 and MA174 and the separation of contacts MA175 and MA85. The separation of contacts MA175 0 ns the circuit for actuating coil MB176 0 the down direction switch of the auxiliary motor. The separation of contacts MA85 further opens the circuit for the actuating coils A84 and B100 of the direction switches of the main motor 11 to prevent its energization during the levellin o ration. The engagement of contacts A1 3 and MA174 completes circuits for the auxiliar motor stator windings 28, 30 and 31 an release coil 32 for the brake 33 of the auxiliary motor. The circuit for stator winding 28 may be traced from wire 124, through wire 177, wire 178, contacts MA173, stator winding 28, to the star point. The circuit for stator winding 30 may be traced from wire 133, through wire 166, wire 180, contacts MA174, stator winding 30 to the star point. The circuit for stator winding 31 may be traced from wire 128 through stator winding 31 to the star point. The brake release coil 32 is connected across stator windings 28 and 30. The energization of coil 32 releases the brake 33 to permit the car to be operated by the auxiliary motor 26.

As hereinbefore stated auxiliary motor 26 15 connected to main motor 11 for driving hoisting sheave 251 to operate the car when main motor brake 22 is applied. Consequently the release of brake 33 for auxiliary motor 26 and energization of the stator windings thereof results in sheave 251 being driven by auxiliary motor 26 to raise the car into accurate alinement with the upper landing. When the car is brought level with the landing, the levelling cam 257 will no longer maintain the levelling switch 34 closed and the circuit for coil MA170 will be interrupted. The deenergization of coil MA170 results in the engagement of contacts MA85 and MA175 and the separation of contacts MA173 and MA174. The engagement of contacts MA17 5 prepares the circuit for coil MB17 6. The engagement of contacts MA85 prepares the circuit for the coils A84 and B100. The separation of contacts MA173 and MA174 interrupts the circuit for the auxiliary motor stator windings and brake release coil 32 and the motor is stopped as brake 33 is applied.

If the elevator car had stopped with the car platform above upper landing, the levelling cam 256 would have operated the levelling mechanism 255 to effect closing of level ling switch 35 to prepare the circuit for actuating coil M13176 of the down direction switch of the auxiliary motor. Coil MB176, upon energization when contacts R130 engage as above described, efi'ects the engagement of contacts MB182 and MB183 and the separation of contacts MB86 and MB172. The separation of contacts MB172 interrupts the circuit of the actuating coil MA170 of the auxiliary motor up direction switch. The 1 circuit for the auxiliary motor stator wind-v ings and brake release coil 32. The circuit for stator winding 28 may be traced from wire 133, through wire 166, wire 184, contacts MB182, stator winding 28 to the star point. The circuit for stator winding 30 may be traced from wire 124, through wire 177, wire 185, contacts MB183, stator winding 30, to the star point. The stator winding 31 is connected directly to wire 128. The brake release coil 32, as previously ointed out, is connected across stator windings 28 and 30. Energization of coil 32, effects the release of brake 33 to permit the auxiliary motor to lower the elevator car into exact alignment with the upper landing. When the elevator car is lowered into alignment with the upper landing the levelling cam 256 no longer maintains levelling switch 35 closed and the circuit for actuatin coil MB172 of the down direction switch 0 auxiliary motor 26 is interrupted. As a result, contacts MB86 and MB172 engage and contacts MB182 and MB183 separate. The engagement of contacts MB17 2 prepares the circuit for coil MA170. The engagement of contacts MB86 prepares the circuits for coils A84 and B100. The separation of contacts MB182 and MB183 results in the deenergization of the stator windings of the auxiliary motor and also of brake release coil 32 and the brake 33 is applied to stop auxiliar motor 26 and bring the car to rest level wit the upper landing.

The elevator car is now at the upper landing and the hatchway door 258 is in open position. The truck upon platform 46 may now be moved into the elevator car. As the truck is moved off platform 46, the platform is returned to its raised position and the platform-switch 53 opens and platform switch 54 closes. The opening of switch 53 further opens the circuit for coil AA80 of the up auxiliary direction switch. The closing of switch 54 prepares the circuit for coil Z65 of the auxiliary door control switch. The coil Z65 is not energized however, since before the rear wheels of the truck are entirely off the landing platform 46 the front wheels will have moved upon the adjacent movable platform 57 in the elevator car, effecting the opening of switch 61 and the closing of switch 60. The opening of switch 61.

113 at the upper landing. It is assumed that the truck does not ride onto platform 58, but if the truck should ride onto and depress this platform the conditions of the circuits is not changed inasmuch as platform switch 63 IS in series with platform switch 61 and platform switch 62 is in parallel with platform switch 60. Thus it will be seen that it is immaterial whether one or both car platforms are depressed.

The car may be caused to travel to the lower landing either by operating one of the down direction car buttons 111 or by operating one of the send buttons 113 at the upper landing. Assume that one of the car buttons 111 is operated. The operation of car button 111 completes the circuit for actuating coil D186 of the down direction relay. The circuit for coil D186 may be traced from wire 66, through contacts T77, wire 78, wire 187, coil D186, push button 111, wire 188, platform switch 60, to wire 72. Upon energization of coil D186, contacts D190, D191 and D192 are engaged.

Upon the engagement of contacts D191 the circuit for actuating coil BB156 of the auxiliary down direction switch is completed. I The circuit for coil BB156 may be traced from wire 66, through contacts T77, contacts F200, limit switch LU153 which is closed since the car is at the upper landing, contacts D191, and coil BB156, to wire 72. The energization of coil BB156 effects the engagement of contacts BB201 to prepare the circuit for actuating coil B100 of the down direction switch of main motor 11. The engagement of contacts D192 completes the circuit for actuating coil E202 of the door release switch. The circuit for coil E202 may be traced from wire 66, through contacts T77, wire 78, coil E202 and contacts D192, to wire 72. The energization of coil E202 effects the separation of contacts E203 for a purpose to be later described. 4

Upon the engagement of contacts D190 a circuit for actuating coil Y75 of the door may be traced from wire 66, through wire 158, coil Y75, wire 193, contacts D190, wire 194, door switch 167, which is closed since the door is in open position, wire 195, limit switch LU155, wire 161, wire 152, contacts A94 and B162, to wire 72.. Upon energization of coil Y7 5 contacts Y196 and Y197 of the door closing switch are engaged to complete the circuit for the stator windings of door operating motor 36 and brake release coil 42. The connection for the door motor stator windings are reverse from those previously traced for the door opening operation, stator winding 38 being connected to wire 133 by contacts Y196 and stator winding 40 being connected to wire 124 through wire 177 by contacts Y197. Brake release coil 42, as previously pointed out, is connected across stator windings 38 and 40. Door operating motor 36 upon operation starts to move the hatchway door to closed position.

closing switch iscompleted. This circuit When the hatchway door is moved from open position switch 160 closes to prepare the circuit for coil X76 of the door opening switch. When the door is fully closed the door switch 167 opens and door switch 92 closes. The Opening of switch 167 interrupts the circuit of coil Y75 causing the contacts Y196 and Y197 of the door closing switch to separate. As a result, the circuits for door motor 36 and its brake release coil 42 are interrupted and the motor stops as brake 43 is applied. It is to be understood that suitable mechanical and/or electricalinterlocks are provided for preventing simultaneous closing of door closing switch Y and door opening switch X.

Upon the closing of door switch 92, along with the closing of switch 92 for the other hatchway door at that floor, the circuit for actuating coil B100 of the down direction switch is completed. This circuit may be traced through stop buttons 118, contacts MA85, contacts MB86, coil B100, wire 204, contacts BB201, limit switch LD150, contacts A93, wire 91, door switches 92, safety devices 64. to wire 72. Upon the energization of coil B100, contacts B88 and B162 are separated and contacts B205, B206, B207, B208 and B209 are engaged, these contacts corresponding with contacts A93, A94, A95, A98, A99, A97 and A96 respectively of the main motor up direction switch. Thus, the auxiliary motor retarding switch R, non-interference switch T and potential switch P are operated and the stator windings of the main motor 11 and brake release motor 21 are connected to the mains to efi'et the starting of the car. The connections for the stator windings of the main motor are reversed so that the car is startedin the down direction, stator winding 13 being connected to wire 133 by contacts B206 and stator winding 15 being connected to wire 124 by contacts B207. Upon the energization of the brake release motor 21, the brake 22 is released and the auxiliary motor is disconnected from the hoisting sheave and, as the main motor is energized, the elevator car starts to move in the down direction. The accelerating switches C and K act as before to short-circuit the starting resistances, finally causing full line voltage to be applied to the main motor stator windings.

As the elevator car leaves the upper landing cam 262 permits the closing of limit switch LU and the opening of limit switches of LU155, and LU154 and limit switch LU153 in succession, these switches performing the same functions as the car leaves the upper landing as performed by the switches LD150, LD151, LD70 and LD81 respectively as the car left the lower landing.

As the elevator car approaches the lower landing cam 262 effects the closing of limit switch LD81, and limit switches LD70 and LD151, and the opening of limit switch LD150 in succession. The closing of switch LD81 prepares the circuit for auxiliary up direction switch coil AA80. The closin of switch LD70 prepares a circuit for coil 65. The coil remains deenergized, however, as the load on the car latform maintains switch 61 open. The closing of switch LD151 prepares a circuit for coil X76 of the door openin switch. However, the circuit for coil X76 remains open at contacts B162 of the down direction switch. The opening of switch LD150 interrupts the circuit for coil B100 of the down direction switch. Upon the deenergization of coil B100 contacts B205, B206, B207, B208 and B209 separate and contacts B88 and B162 engage. As a result, the brake 22 is applied to stop the main motor and bring the car to rest at the lower floor. In the event that the car stops out of alignment with the landing at the lower floor, the levelling mechanism will operate at the expiration of a predetermined time interval, as previously described, to bring the car to an exact landing level. Although contacts B209 separate on deenergization of coil B100 the circuit for actuating coils T102 and P103 of the non-interference and potential switches are maintained closed by contacts T107.

As the elevator car reached the door operating zone at the lower landing the cams 261 carried by the car engaged impact members 272 of latch levers 271 to unlock the hatchwa y door at the lower landing. The engagement of contacts B162, upon the dropping out of the down direction switch, completed a circuit for coil X76 of the door opening switch, this circuit being through contacts Z73, which are engaged because of the opened car platform switch 61, and through limit switch LD151. Upon the energization of coil X76, the door opening switch contacts X163 and X164 are engaged and the door operating motor 36 is operated to open the hatchway door at the lower landing in the same manner as described for opening the hatchway door at the upper landing.

The elevator car is now at the lower landing and the hatchway doors at that landing are in open position. The truck may be moved out of the elevator car to the landing. It will be assumed that the truck is backed ofl' the car onto landing platform 44. As

the truck is moved off the car platform 57,

the platform switch opens and switch 61 closes. The opening of switch 60 opens the circuit for coil U235, thus preventing the dispatching of the car by the send buttons 112 or the car buttons 110. The closing of switch 61 does not result in the energization of coil Z65 for, before the truck is entirely off the car latform, its front wheels are upon the landlng platform 44 effecting the opening of switch 50 and the closing of switch 48. The

coil Z65 open. The closing of switch 48 does not result in the energization of auxiliary" down direction switch coil BB156 for, as the car is at the lower landing, the limit switch LU153 at the upper landing is open to maintain the circuit for this coil interrupted. As the truck is moved off the landing platform 44, vswitch 48 opens and switch 50 closes. The opening of switch 48 further interrupts the circuit for coil B13156. The closing of platform switch 50 completes the circuit through wire 68 for actuating coil Z65 of the auxiliary door control switch. This causes the closing of the lower floor hatchwa door in the manner previously described, t e circuit for coil Y7 5 of the door closing switch being from wire 66, through wire 158, coil Y75, wire 288, contacts Z74, wire 195, contacts 167 which are engaged since the door is in open position, contacts LD151, and thence to wire 72 as previously traced.

It will be apparent, from the operations described above, that when a load is placed upon a landing platform at either of the landings with the car at the other landing, the car is summoned to the landing at which the platform is depressed and upon its arrival the hatchway door at that landing automatically opens. The. hatchway door remains open until the load is moved away from the landing platform or, upon its movement into the car, until a sending button'or car button is pushed to operate the car, whereupon the hatchway door automatically closes. In order that the elevator car may be summoned to a landing, and the hatchway door may automatically open upon the arrival of the'car, without the necessity of placing andleaving a load upon the movable platforms at the landings, the push buttons 114 and 115 are provided at the upper and lower land-- ings, respectively. These push buttons ala' control door holding switches adapted to control the circuits for auxiliary door control switch actuating coil Z65 so that upon the arrival of the car the hatchway doors will remain in open position. As a result, upon the operation of one of these call buttons the car will be summoned to the landing at which the call button is located and the hatchway door will open and will remain in open position preventing the car from being taken away by operation of other controls including the platform switches. These call buttons are particularly useful for obtaining the exclusive use of the car at a floor at which the immediate arrival of baggage is contemplated.

that landing, as above described, a call but-- ton 114 at the upper landing is operated.

The operation of push button 114 results in;

the energization of actuating coil F212 of the door holding switch. This circuit may be traced from wire 66, through wire 213, contacts E203, coil F212, push button 114, wire 214, door release buttons 116 at the u per landing, contacts G215, to wire 72.

nergization of coil F212 results in the separation of contacts F200, F217 and F218 and the engagement of contacts F220, F221 and F222. The separation of contacts F200 further opens the circuit for the coil BB156 of the auxiliary down direction switch. The separation of contacts F218 opens the eucuit for actuating coil G216 of the door holding switch controlled by the call buttons 115 at the lower landing. The engagement of contacts F220 establishes a holding circuit through wire 223 for coil F212. The engagement of contacts F221 completes a circuit for the signal lanterns 224 at the lower .landing to indicate that the car is in use. The circuit for lanterns 224 may be traced from wire 225, which is connected to a suitable power source, through lanterns 224, contacts F221, to wire 226 which is connected to another wire of the power source. The engagement of contacts F222 completes a circuit for actuating coil AA8O of the auxiliary up direction switch. This circuit may be traced from wire 66, through contacts T77, Wire 78, wire 79, coil AA80, wire 287, contacts F222, wire 227, lower limit switch LD81, contacts G82, to wire 72. Coil AA80 upon energization effects the engagement of contacts AA83 energizing actuating coil A84 of the main motor up direction switch. The up direction switch, upon operation, causes the starting of the elevator car on 1ts tr1p to the upper landing as previously descrlbed.

Should call button 114 have been operated before the hatchway door at the lower floor was closed but after the pushing of a car button to dispatch the car to the lower landing, the call remains effective and the car will be started toward the upper landing after the car has been unloaded at the lower floor and the hatchway door at that floor is closed. This is due to the fact that upper landing door holding switch F establishes its own holding circuit and is thereby held in operated condition once the call button is operated. The same holds true for a call button 115 at the lower landing owing to the fact that lower landing door holding switch G establishes its own holding circuit.

Contacts F217, upon disengagement, open the circuit through wire 69 for coil Z65. As the car leaves the lower landing, limit switch LD opens interrupting the circuit through wire 68 for coil Z65. Since the circuit for coil Z65 is now opened both in wires 68 and 69, the coil becomes deenergized permitting contacts Z73 to engage to prepare the circuit for door opening switch coil X76. As the car approaches the upper landing limit switch LU155 is closed to further prepare the circuit for coil X76. Upon the arrival of the car at the upper landing the contacts A94 engage, as the up direction switch opens, completing the circuit for coil X76 to effect the opening of the hatchway door as previously described.

The hatchway door, upon openin remains in open position because coil 65 of the auxiliary door control switch is maintained deenergized due to the separation of contacts F217 and the open condition of limit switch LD70. Contacts F217 in turn are maintained separated because coil F212 is maintained energized through contacts F220. The elevator car cannot be summoned to the lower floor by operation of a call button 115, or by placing a load upon the landing platforms 44 or 45, and the car remains under the control of the individual who called the car to the upper landing.

Assume now that a truck is moved upon the platform 47, at the right hand side of upper landing, as a result, switch 55 closes and switch 56 opens. The closing of switch 55 tends to complete a circuit for auxiliary up direction switch coil AA80 but coil AA80 is not energized for, as the car is at the upper landing, lower limit switch LD81 is open. The opening of switch 56 further opens the circuit through wire 69 for coil Z65. When the truck is moved off the platform 47 into the car switch 55 opens and switch 56 closes. The opening of switch 55 further opens the circuit for coil AA80. The closing of switch 56 prepares the circuit through wire 69 for coil Z65. As the truck is moved onto car platform 58 switch 63 opens and switch 62 closes. The opening of switch 63 further opens the circuits for coil Z65. The closing of switch 62 prepares a circuit for coil D186 of the down direction relay to enable the car to be taken or sent to the lower floor by operation of a down direction button 111 in the car or a down direction send button 113 at the upper landing. Assume that a send button 113 at the upper landing is operated to send the car to the lower landing. This completes a circuit for actuating coil D186 of the down direction relay. This circuit may be traced from wire 66 through contacts T77, wire 78, wire 187, coil D186, button 113, wire 188, car platform switch 62 which is closed because of the load in the car, to wire 72. Upon the energization of coil D186, contacts D190, D191 and D192 are engaged. Upon the engagement of contacts D191 a circuit is prepared for coil BB156 of the auxiliary down direction switch.

Upon the engagement of contacts D192 the circuit for actuating coil E202 of the door release switch is completed. This circuit for coil E202 has been traced previously. Upon the energization of coil E202 contacts E203 are separated.. Theseparation of contacts E203 results in the deenergization of coil F212 of the up er landing door holding coil Z65.

switch. Upon t e deenergization of coil F212 contacts F200, F217 and F218 engage and contacts F220, F221 and F222 separate. The separation of contacts F220 is in preparation for a subsequent operation. The separation of contacts F221 deenergizes lanterns 224 and the in use signals at the lower land ing are no longer displayed. The separation of contacts F222 further opens the circuit for coil AA80. The en agement of contacts F218 prepares a circuit for coil G216 of the door holding switch controlled by the call buttons 115 at the lower landing. The engagement of contacts F200 together with the engagement of contacts D191 completes a circult, as previously traced, for energizing actuating coil BB156 of the main motor auxiliary down direction switch. On energization of coil BB156 contacts BB201 engage to prepare a circuit for actuating coil B100 of the main motor down direction switch. The engagement of contacts F217 further preares a circuit through wire 69 for coil Z65. l lowever, coil Z65 is not energized as its circuit is maintained open at car platform switch 63 which is open because of the presence of a truck in the car.

On en agement of contacts D190 the actuating coil Y75 of the door closin switch is energized. This circuit for coil Y5 has been traced previously. Upon ener ization of coil Y75 contacts Y196 and Y197 o the door closing switch are engaged to effect the closing of the hatchwa door as described previously. On closing of oor switches 92, as-both doors at the upper landing reach closed position, a circuit is completed for actuating coil B100 of the down direction switch. When the down direction switch closes, the car is operated in the down direction and upon its arrival at the lower landing the hatchway doors will automatically open, all as previously described.

Assume that the truck is moved off the car platform 58 onto the movable platform 45 at the lower landing. As a result switch 62 opens and switch 63 closes. The opening of switch 62 opens the circuits controlled by the dispatching buttons 112,113 at the lower and upper landings and the up and down direction buttons 110 and 111 in the car. The closin of switch 63 tends to energize owever, coil Z65 will not be energized for as the truck is moved onto the platform 45 theplatform switch 52 is opened to maintain coil Z65 deenergized. Platform switch 51 closes as switch 52 opens but is ineffective to energize coil B13156 of the auxiliary down direction switch since as the car is at the lower landing limit switch LU153 for the upper landing is open. When the truck is moved entirely ofi' platform 45 switch 51 opens and switch 52 closes. The opening of switch 51 further interru ts the circuit for coil B13156. The closingo switch 52 together with the closing of switch 63 completes the circuit through wire 68 for coil Z65. The energization of coil Z65 effects the 7 separation of contacts Z73 and the engagement of contacts Z74. The separation of contacts Z73 further opens the circuit for door opening switch coil X76. The engagement of contacts Z74 results in the energization of coil Y7 5 and the operation of motor 36 to close the hatchway door as previously described.

Assume now that a truck is to be taken to the upper landing but that, although the control of the elevator car is desired immediately, the truck is not yet prepared for the trip. To insure that the elevator car will be available when needed the call button .115 at the lower landing is operated. This causes the energization of the actuating coil G216 of the door holding switch. The circuit for coil G216 may be traced from wire 66, through wire 213, contacts E203, wire 228, contacts F218, the door release buttons 117 at the lower landing, call button 115, coil G216, wire 214, to wire 72. gization of coil G216 effects the separation of contacts G71, G215 and G82 and the engagement of contacts G230, G231 and G232. The engagement of contacts 231 establishes a holding circuit through wire 233 for coil G216. The engagement of contacts G230 completes a circuit for the in use lanterns 234 at the upper landing. This circuit may be traced from wire 225, through lanterns 234, contacts G230, to wire 226. The engagement of contacts G232 tends to complete a circuit for coil BB156 of the auxiliary down direction switch. However, as the elevator car is already at the lower landing the limit switch LU153 is open and coil BB156 will not. be energized. The separation of contacts G82 opens the circuit for coil AASO of the auxiliary up direction switch; the

' separation of contacts G215 opens the circuit for coil F212 of the door holding switch controlled by the call buttons 114 at the upper landing.

The separation of contacts G71 results in the deenergization of coil Z65 of the auxiliary door control switch. As a result contacts Z74 separate to interrupt the circuit for door closing switch coil Y75, and contacts Z73 engage to complete a circuit for door opening switch coil X76. Upon the engagement of contacts X163 and X164 of the door opening switch, the lower landing hatchway door is caused to open as previously described.

The opening of switches 92 as both doors at the lower landing open prevents the completion of circuits for the direction switch coils for the main motor 11.

The hatchway doors on opening will re- The enermain in open position since contacts Z74 which control door closing switch coil Y75 are separated as coil Z is maintained deenergized. Coil Z65 remains deenerglzed since switch LU154 for the upper landing is open as the car is at the lower landing, and contacts G71 are separated. Contacts G71 in turn are maintained separated as the holding circuit for coil G216 is maintained through contacts G231.

To restore the elevator car to service, coil G216 must be deenergized to permit the hatchway doors at the lower landing to close for, as long as the doors are held in open position, the elevator car cannot make a trip to the upper landing in response to the presence of a load upon the movable platforms at the upper landing or in response to the operation of the call buttons 114 at the upper landing. Assume that it is found that the use of the car at the lower floor is not needed. The elevator car may be restored to service without causing it to travel to the upper landing by operation of a door closing button 117 at the lower landing. The operation of button 117 interrupts the circuit for coil G216. When coil G216 deenergizes contacts G230, G231 and G232 separate and contacts G71, G215, and G82 engage. The separation of contacts G231 is in preparation for a subsequent operation. The separation of contacts G230 interrupts the circuits for the in use lanterns at the upper landing. Upon the separation of contacts G232 the circuitfor coil B13156 of the auxiliary down direction switch is further opened. Upon the engagement of contacts G82 the circuitfor coil A1480 of the auxiliary up direction switch is prepared. Upon the engagement of contacts G215 the circuit for door holding switch coil F212 controlled by call buttons 114 at the upper landing is prepared. Upon the engagement of contacts G71 a circuit is completed for coil Z65. This circuit may be traced from wire 66. through wire 67. coil Z65. wire 68, limit. switch LD70, lower landing platform switches 50 and 52. contacts G71, car platform switch contacts 61 and 63, to wire 72. Energization of coil Z65 effects the separation of contacts Z73 and the engagement of contacts Z74. The separation of contacts Z73 further opens the circuit for door opening switch coil X76. The engagement of contacts Z74 completes a circuit for door closing switch coil Y75. lVhen the door closing switch operates the hatchway doors are moved to closed position as previously described. The elosing of door switches 92 as the doors reach closed position prepares the circuits for the up and down direction switch coils A84 and B100.

Assume again that the elevator car without load is at rest at the lower landing and that the hatchway doors are closed. Assume also that there is no load upon any of the landing platforms. The hatchway doors at the lower landing may be caused to be 0 ned by moving the truck upon the movable landing platform 44 at the lower landing. The presence of the truck upon the lower landing platform causes platform switch 50 to open and switch 48 to close. The closing of switch 48 tends to complete a circuit for auxiliary down direction switch coil B13156. However, as the elevator car is at the lower landing limit switch LU153 for the upper landing is open and coil B13156 is not energized. The opening of switch 50 interrupts the circuit for coil Z65. Contacts Z74 separate and contacts Z73 engage. The separation of contacts Z74 further opens the circuit for coil Y7 5. The engagement of contacts Z73 completes a circuit for door opening switch coil X76 and the hatchway door at the lower landing is opened as previously described. The opening of switches 92 as both hatchway doors at the lower landing move from closed position opens the circuit for main motor direction switch coils A84 and B100 to prevent operation of the car by means of controls at the upper landing.

1 ssume that the truck is moved into the car from platform 44. Thus switch 48 opens and switch 50 closes. The opening of switch 48 further opens the circuit for coil B13150. The closing of switch 50 tends to complete the circuit to energize coil Z65. However. coil Z65 is not energized for before the rear wheels of the truck leave the landing platform 44 the front wheels are upon the adjacent car platform 57 effecting the opening of switch 61 and the closing of switch 60. The opening of switch 61 maintains the circuit for coil Z65 interrupted. The closing of switch 60 prepares'the circuit for actuating coil U235 of the up direction relay to enable energization of this coil to control car movement in the up direction by means of an up direction car button 110 or an up direction sending button 112 at the lower landing.

Assume that an up direction send button 112 at the lower landing is operated with the lower landing platforms both in raised position, the operation of button 112 completes a circuit for coil U235. The encrgization of coil U235 results in the engagement of contacts U236, U237 and U238. The engagement of contacts U238 energizes coil E202 of the door releasing switch causing contacts E203 to separate. The circuit for coil E202 maybe traced from wire 66 through contacts T77. wire 78, coil E202, contacts U238 to wire 72. The separation of contacts E203 further opens the circuits for actuating coils F212 and G216 of the door holding switches. The engagement of contacts U237 completes a circuit for coil AASO of the auxiliary up direction switch. This circuit in. Y be traced from wire 66, through contacts T 7, wire 78, wire 79, coil AA80, contacts U237, wire 227, lower limit switch LD81, contacts G82 to wire 72. Energization of coil AA80 effects the engagement of contacts AA83 to prepare a circuit for coil A84 of the up direction switch. The engagement of contacts U236 completes a circuit for coil Y7 5 of the door closing switch. This circuit for coil Y is from wire 66, through wire. 158, coil Y75, wire 288, wire 239, contacts U236, wire 194, wire 195, switch 167, limit switch LD151, wire 161 and thence to wire 72 as previously traced. Switch Y, upon operation causes the hatchway door at the lower landing to be moved to closed position as prevlously described. The closing of switches 92, as both lower landing doors reach closed position, completes the circuit for actuating coil A84 of the up direction switch resulting in movement of the car in the up direction as previously described. Upon arrival of the car at the upper floor the hatchway doors open automatically as previously described. U on moving the truck out of the car and o the landing platform 46 or 47 the hatchway doors close automatically, the car platform switches and landing platform switches at the u per landing functioning in a manner simi ar to that described for the corresponding operation at the lower landing.

The elevator car may be stopped at any point from within the car, as under emergency conditions, by operation of a stop button 118 which renders all control circuits ineffective. These stop buttons may also be employed to stop the car under conditions where it is desired to effect a change in destination.

Push buttons 242 and 243 are located on the control panel 254. These buttons are arranged to control the actuating coils of the main motor direction switches A and B, and are provided to permit control of the elevator car from the control room when desired. These buttons may be omitted, in case they are not required for the particular installation.

It is believed that other operations, such as the summoning of the car to the lower landing by the presence of a load upon landing platforms 44 or 45 at the lower landing or the opening of the hatchway doors at the upper landing by movement of a load onto the landing platforms 46 or 47 when the car is at the upper landing, will be apparent from the above description of the unctioning of the control system and need not be described in detail.

It will be seen from previous description that when a load is placed upon a landing platform at a floor other than that at which the car is located the depression of the landing platform summons the car to that landing and causes the hatchway doors to open to permit access to the car. When the load is placed upon a landing platform at the floor at which the car is positioned, the depression of the platform efiects the o nin of the hatchway doors at that landirig g The presence of a load upon the car platform or latforms renders the car buttons and sending buttons effective to cause the closing of the hatchway doors and to dispatch the car to the other landing. The presence of a load upon the car platform also causes the opening of the hatchway doors at the other landing upon arrival of the car thereat.

The hatchway doors, when open as the result of the presence of a load upon a landing platform or on a car platform, remain open so long as the landing platform is depressed. The presence of a load upon a landing platform at one floor, or on a car platform, also renders the landing platform and call buttons at other floors ineffective to control the operation of the car or of the hatch way doors. The restoration of the depressed landing platform at the floor at which the car is positioned to its raised position results in the closin of the hatchway doors, provided the ot er landin platform at that floor and both car plat orms are in raised position.

The car may be summoned to a floor by operating a call button at that floor. Upon arrival of the car at the floor the hatchway doors thereat are caused to open and remain open. The call buttons at the floor at which the car is positioned also act upon operation to cause the hatchway doors at that floor to open and remain open. When (the hatchway doors have opened as a result of the operation of a call button they may be reclosed by the operation of a door closing button at that floor. They are also reclosed when a car button or a sending button is operated to cause the car to travel to another floor. When the car is under the control of a call button at either floor, the other floor to indicate that the car is in use and the movable platforms, call buttons and sending buttons at the other floor are ineffective to cause the operation of the hatchway doors or the elevator car.

It is preferred to lock the sending buttons 112 and 113 and the call buttons 114 and 115 against operation, their operation being effected only through unlocking devices, such as keys, entrusted to certain individuals in the building. In this manner the operation of the car through the intermediary of these controls is restricted to certain individuals. The door closing buttons 116 and 117 at the respective landings may also be arranged for ,key operation, as for example by arranging these buttons and their corresponding call buttons as units, each unit being under the control of a single key. The feature of subjecting buttons to ke control may be applied only to certain of t ese buttons, or may be lights are lighted at omitted entirely, depending on the requirements of the articular installation.

As hereinbe ore stated, the control system is not limited to an elevator installation of only two floors. In case of an installation of more than two floors, full sets of car buttons are provided in the elevator car, one button of each set for dispatching the car to each floor served. Also, sets of sending buttons are provided at each floor and arranged so that the car may be dispatched from any floor to any of the other floors. Call buttons and door closing buttons are also provided at each floor. It may be desirable, however, to provide call buttons and door closing buttons only at certain floors and, in case of a two floor installation, call buttons and door closing buttons may be provided at only one of the floors if desired. In this way, the operation of calling the car and thereafter effecting the closing of the hatchway doors may be restricted to those floors at which such operation is deemed desirable. In case call buttons are provided only at one floor, the in use lights at that floor may be omitted. On the other hand, in use lights may be provided at all floors and arranged so that all will be lighted in response to any call button.

When the installation is arranged for more than two floors, movable landing platforms are provided at each floor served. The movable platforms at the landings, as well as those in the car, may be arranged to control the operation of car gates or other closure means, if desired, in addition to controlling the operation of the hatchway doors.

To prevent the operation of the car, or the closure means affording access thereto, by means of the landing platforms when such operation is not intended, a dash-pot controlled switch or other timing device may be arranged to control the closure operator and car moving means to prevent movements,

of the platforms by transitory loads causing operation of the closure means or the car. This result may also be effected by providing a pair of movable platforms at each side of the hatchway at each landing and spacing the platforms of each pair so that they may be depressed by the front and rear wheels of a baggage truck. In such event, suitable controls are provided for operation by the platforms and are arranged, in conjunction with suitable control apparatus, so that the depression of one of a pair of platforms alone is not effective to initiate the operation of either the hoisting mechanism or door operating mechanism, so that the depression of both platforms of a pair is effective to control the hoisting and door operating mechanism, and so that the depression of one of the platforms of a pair is effective to cause the door operating mechasystems.

nism to maintain the hatchway doors in open position.

Depressible platforms at the landings and in the elevator car have been described for controlling the operation of the car and the hatchway doors but it is to be understood that other types of movable platforms may be employed. Also. movable approaches other than platforms, such as guards or lever mechanis1ns,1nay be employed at the landings if desired. In fact,any device which is responsive to the presence of a load for the car at a landing, or a load in the car, may be employed, such devices including photoelectric cells, thermionic tubes and magnetic devices. all of which are within the contemplation of the invention.

Although the invention has been described as applied to a freight elevator installation, it is also applicable to passenger elevator \Vheu the invention is applied to a passenger elevator system, the control of the elevator car and hatchway doors is effected by the presence of an intending passenger at a landing or a passenger in the car in the same manner as previously described for the presence of a truck at a landing or in the car. In certain types of passenger elevator systems in which the starting and stopping of the car are controlled by the intending passengers themselves and in other types of passenger elevator systems in which the intending passengers control only the stopping of the car, such control operations may be effected by the presence of the intending passengers at the landings in accordance with the principles of the invention. Such systems include those in which a passenger or intending passenger is able to obtain exclusive control of the car, and those in which such preference feature is omitted. such as systems in which the car may be intercepted by intending passengers at the landings or those in which collective operation is provided. It is to be understood that in applying the invention to passenger elevator systems, certain features may be omitted, such as the entrance and exit features for one side of the car rendering the operation of the system subject to the presence of a load in the car, the provision of send buttons at the landings, and the provision of call buttons and door closing buttons at the landings.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In an elevator system; a hatchway; an

elevator car therein; a landing served by said car; means for moving said car in sald hatchway and for stopping it at sald landing; a manually operable control for said landing; and means responsive to the presence of a load in said car and to the operation oi said manual control for causing said car moving and stopping means to move said car to and stop it at said landing.

2. In an elevator system; a hatchway; an elevator car therein; a landing served by said car; means for moving said car in said hatchway and for stopping it at said landing; a manual control for said landing; and means responsive to a load in said car for rendering said manual control effective, up on operation, to cause said car movin and stopping means to move said car to an stop it at said landing.

3. In an elevator system; a hatchway; an elevator car therein; a plurality of landings served by said car; means for moving said car in said hatehway and for stopping it at said landings; a manually operable con trol for each of said landings; a movable platform in said ear; and means responsive to a load on said platform for rendering said manual controls effective to cause said car moving means to move said car to and stop it at the landings corresponding to the manual controls operated.

4. In an elevator installation; a hatchway; a car in said hatchway; a landing served by said car; closure means adapted when open to afford access to said car; a movable approach at said landing operable by loads for or from the elevator car; and means responsive to the operation of said movable approach by the arrival of the load for said car to cause the opening of said closure means, provided said car is positioned at said landing, and responsive to the operation of said movable approach bydeparting loads for causing the closing of said closure means.

5. In an elevator installation; a hatchway; a car in said hatchway; a landing served by said car; closure means adapted when open to afford access-to said car; means for operating said closure means; a movable platform at said landing, said platform being biased to raised position; and control means operated by depression of said platform to cause said closure operating means to open said closure means, provided said car is positioned at said landing, said control means causing said closure operating means to close said closure means when said platform is in raised position.

6. In an elevator installation; a hatchway; an elevator car therein; a landing served by said car; means for moving said car in said hatchway and for stopping it at said landing; closure means adapted when open to afford access to said car; operating means for said closure means; a manually operable control for said landing for causing said car moving and stopping means to move said car to and stop it at said landing; and means responsive to the presence of a load in the car for causing said closure operating means to open said closure means upon arrival of the car at said landing in response to the op eration of said manually operable control.

7 In an elevator installation; a hatchway; an elevator car therein; a plurality of landings served by said car; means for moving said car in said hatchway and for stopping it at said landings; closure means adapted when open to afford access to said car; operating means for said closure means; a manually operable control for each landing, each control upon operation causing said car moving and stopping means to move said car to and stop it at the landing corresponding to the control operated; a movable platform in said car; and control means operated by depression of said platform to cause said closure operating means to open said closure means at the landing corresponding to the control operated upon arrival of the car thereat.

8. In an elevator installation; a hatchway; an elevator car therein; a. plurality of landings served by said car; a hatchway door at each landing; operating means for said hatchway doors; means for moving said car in said hatchway and for'stopping it at said landings; operating controls for each landing, each operating control upon operation being adapted to cause said car moving and stopping means to move said car to and stop it at the landing corresponding to the operating control operated; a movable platform in said car; a movable platform at each of said landings; said car platform and said landing platforms being biased to raised position; means 0 erated by depression of said car platform or rendering said operating controls efi'ective to cause said car moving means to move said car to and stop it at their respective landings and to cause said hatchway door operating means to open the hatchway door at the landing corresponding to the operating control operated upon arrival of the car thereat; and means for each of said landing platforms adapted to be operated upon depression thereof, said car platform operated means and said landing platform operated means for the landing at which a stop is made causing the operation of said hatchway door operating means to close the hatchway door at such landing when such platforms are in raised position.

9. In an elevator installation; a hatchway; a car in said hatchway; a plurality of landings served by said car; means for moving said car in said hatchway and for stopping it atsaid landings; a push button outside the car foreach of said landings; a plurality of push buttons within said car, one 

